PointSlope Form Example 1 Find the equation of

Point-Slope Form

Example 1 Find the equation of a line (slope-intercept form) passing through point (2, -3) with slope of -5 m is given (-5) What we Know: x=2 y = -3 m = -5 y = mx + b Finding b: y = mx + b -3 = -5(2) + b -3 = -10 + b 7=b b is not given, so we must find it Therefore: y = -5 x + 7

Example 2 Find the equation of a line (slope-intercept form) passing through point (4, -1) with slope of 7 m is given (7) What we Know: x=4 y = -1 m=7 y = mx + b Finding b: y = mx + b -1 = 7(4) + b -1 = 28 + b -29 = b b is not given, so we must find it Therefore: y = 7 x – 29

Example 3 Find the equation of a line (slope-intercept form) passing through point (-5, -3) with slope of 9 m is given (9) What we Know: x = -5 y = -3 m=9 y = mx + b Finding b: y = mx + b -3 = 9(-5) + b -3 = -45 + b 42 = b b is not given, so we must find it Therefore: y = 9 x + 42

Example 4 Find the equation of a line (slope-intercept form) passing through point (1, -2) with slope of 3 m is given (3) What we Know: x=1 y = -2 m=3 y = mx + b Finding b: y = mx + b -2 = 3(1) + b -2 = 3 + b -5 = b b is not given, so we must find it Therefore: y = 3 x – 5

Using Point Slope Form y – y 1 = m(x – x 1)

Example 5 Find the equation of a line (slope-intercept form) passing through point (1, -2) with slope of 3 y – y 1 = m(x – x 1) y – (-2) = 3(x – 1) y + 2 = 3 x – 3 Point Slope Form Plug in values Use distributive Property y = 3 x – 5 Subtract 2

Example 6 Find the equation of a line (slope-intercept form) passing through point (3, 5) with slope of 6 y – y 1 = m(x – x 1) y – 5 = 6(x – 3) y – 5 = 6 x – 18 Point Slope Form Plug in values Use distributive Property y = 6 x – 13 Add 5

Example 7 Find the equation of a line (slope-intercept form) passing through point (-3, 5) with slope of -2 y – y 1 = m(x – x 1) y – 5 = -2(x – (-3)) y – 5 = -2(x + 3) y – 5 = -2 x – 6 Point Slope Form Plug in values Rewrite as Use distributive Property y = -2 x – 1 Add 5

Example 8 Find the equation of a line (slope-intercept form) passing through point (7, 8) with slope of -2 y – y 1 = m(x – x 1) y – 8 = -2(x – 7) y – 8 = -2 x + 14 Point Slope Form Plug in values Use distributive Property y = -2 x + 22 Add 8